diff options
Diffstat (limited to 'src/stmf0/ao_adc_fast.h')
| -rw-r--r-- | src/stmf0/ao_adc_fast.h | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/src/stmf0/ao_adc_fast.h b/src/stmf0/ao_adc_fast.h new file mode 100644 index 00000000..eec45505 --- /dev/null +++ b/src/stmf0/ao_adc_fast.h @@ -0,0 +1,89 @@ +/* + * Copyright © 2015 Keith Packard <keithp@keithp.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + */ + +#ifndef _AO_ADC_FAST_H_ +#define _AO_ADC_FAST_H_ + +void +ao_adc_read(uint16_t *dest, int len); + +void +ao_adc_init(void); + +/* Total ring size in samples */ +#define AO_ADC_RING_SIZE 256 +/* Number of samples fetched per ao_adc_start call */ +#define AO_ADC_RING_CHUNK (AO_ADC_RING_SIZE >> 1) + +extern uint16_t ao_adc_ring[AO_ADC_RING_SIZE]; + +#define ao_adc_ring_step(pos,inc) (((pos) + (inc)) & (AO_ADC_RING_SIZE - 1)) + +extern uint16_t ao_adc_ring_head, ao_adc_ring_tail; +extern uint8_t ao_adc_running; + +void +_ao_adc_start(void); + +static inline uint16_t +_ao_adc_remain(void) +{ + if (ao_adc_ring_tail > ao_adc_ring_head) + return AO_ADC_RING_SIZE - ao_adc_ring_tail; + return ao_adc_ring_head - ao_adc_ring_tail; +} + +static inline uint16_t +_ao_adc_space(void) +{ + if (ao_adc_ring_head == ao_adc_ring_tail) + return AO_ADC_RING_SIZE; + if (ao_adc_ring_head > ao_adc_ring_tail) + return AO_ADC_RING_SIZE - ao_adc_ring_head; + return ao_adc_ring_tail - ao_adc_ring_head; +} + +static inline uint16_t * +ao_adc_get(uint16_t n) +{ + if (ao_adc_ring_tail + n > AO_ADC_RING_SIZE) + ao_panic(AO_PANIC_ADC); + ao_arch_block_interrupts(); + while (_ao_adc_remain() < n) { + if (!ao_adc_running) + _ao_adc_start(); + ao_sleep(&ao_adc_ring_head); + } + ao_arch_release_interrupts(); + return &ao_adc_ring[ao_adc_ring_tail]; +} + +static inline void +ao_adc_ack(uint16_t n) +{ + if (ao_adc_ring_tail + n > AO_ADC_RING_SIZE) + ao_panic(AO_PANIC_ADC); + ao_arch_block_interrupts(); + ao_adc_ring_tail += n; + if (ao_adc_ring_tail == AO_ADC_RING_SIZE) + ao_adc_ring_tail = 0; + if (!ao_adc_running && _ao_adc_space() >= AO_ADC_RING_CHUNK) + _ao_adc_start(); + ao_arch_release_interrupts(); +} + +#endif /* _AO_ADC_FAST_H_ */ |